(19)

(11)

EP 2 191 096 A2

(12)

(88) Date of publication A3: 04.06.2009 (43) Date of publication: 02.06.2010 Bulletin 2010/22 (21) Application number: 08828381.7 (22) Date of filing: 27.08.2008

(51) International Patent Classification (IPC):  E21B 7/04(2006.01) E21B 7/06(2006.01) E21B 41/00(2006.01) (86) International application number: PCT/US2008/010151 (87) International publication number: WO 2009/029269 (05.03.2009 Gazette 2009/10)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR Designated Extension States: AL BA MK RS (30) Priority: 27.08.2007 US 966297 P (71) Applicant: Vermeer Manufacturing Company Pella, IA 50219 (US)	(72) Inventors: RUNQUIST, Randy, Ray Knoxville, IA 50138 (US) KELPE, Hans Pella, IA 50219 (US) (74) Representative: Klinghardt, Jürgen et al Eisenführ, Speiser & Partner Johannes-Brahms-Platz 1 DE-20355 Hamburg DE-20355 Hamburg (DE)